Examine source code of MultiFreeca

{
  "manifest_version": 3,
  "name": "MultiFreeca",
  "description": "여러 아프리카TV 방송을 함께 볼 수 있습니다.",
  "version": "1.2.1",
  "icons": {
    "16": "icon-16.png",
    "32": "icon-32.png",
    "48": "icon-48.png",
    "128": "icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "multifreeca@chatlink.app"
    }
  },
  "permissions": [
    "cookies"
  ],
  "host_permissions": [
    "https://play.afreecatv.com/*",
    "https://m.afreecatv.com/*",
    "*://afreecatv.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://play.afreecatv.com/*"
      ],
      "css": [
        "content.css"
      ],
      "js": [
        "content.js"
      ],
      "all_frames": true,
      "run_at": "document_end"
    },
    {
      "matches": [
        "https://m.afreecatv.com/*"
      ],
      "css": [
        "mobile.css"
      ],
      "js": [
        "mobile.js"
      ],
      "all_frames": true,
      "run_at": "document_end"
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "mobile-embed.js"
      ],
      "matches": [
        "https://m.afreecatv.com/*"
      ]
    }
  ]
}